STATEN ISLAND, N.Y. - Political and scientific leaders recently made their own waves as they debated plans for post-Hurricane Sandy protection aboard a luxury yacht touring New York Harbor.

Professional opinions differed between a representative of the mayor's office and a leading engineer who took the floor on the top deck of the Zephyr, which left South Street Seaport in Manhattan on a two-hour trip sponsored by the Working Harbor Committee that included much of Staten Island's North and West shores.

The tour was called "Beyond Sandy," and for paying customers, it brought together top minds to debate the best ways the city can brace itself for future storms.

William Haas, senior policy advisor to Mayor Bloomberg's Special Initiative for Rebuilding and Resiliency (SIRR), outlined a "layered strategy" that includes Staten Island-specific projects to add sand dunes and to raise and armor the South Beach boardwalk with sturdy structures in preparation for future storms.

"Integrating that into the boardwalk would provide protection for a large portion of the East Shore of Staten Island," Haas said. "The Army Corps has actually been looking at that project since the 1990s. That project needs to be moved forward. When the Army Corps is involved, there is a lot of process involved, and sometimes that can delay projects that, even if people think there is a lot of sense behind it, there may be a lot of issues that will stall it." 

NOT SUFFICIENT? 

But those improvements won't be sufficient according to Mike Abrahams, technical director for structures at the engineering firm Parsons Brinckerhoff.

"That would improve conditions and it would help improve the vulnerability to smaller storms," Abrahams said. "But my thesis is that those types of measures, while they are helpful, don't really address the long term problems that we are facing."

Abrahams said not only will the effects of global warming and rising water levels make Sandy-sized storms more frequent, but they will also allow smaller storms to inflict similar damage.

"The 100-year storm now has to be considered a much more frequent storm," he said. "The 10-year-storm becomes the three-year storm, and so on."

Abrahams introduced to the audience on the Zephyr his plan to install three floodgates in major city waterways. The gates would be similar to those constructed in London and those proposed for cities like Saint Petersburg, Russia, and Venice, Italy, designed to protect coastal cities from surges and wave action caused by storms Sandy-sized and above.

Located in the East River, the Kill van Kull and either the Arthur Kill or the waters off Sandy Hook, N.J., the gates would protect New York City in ways the mayor's plan could not, Abrahams said. But it's the project's projected price tag of around $20 billion that makes its completion improbable.

"It is definitely not something to forget about," said Dr. Philip Orton, a research oceanographer at Stevens Institute of Technology in Hoboken, N.J. "The city decided to forget about it, right?"

Abrahams believes there are multiple reasons why this is. For one, there is environmental concern that the massive water gates -- which would need to protrude more than 20 feet out of the water -- would negatively affect water flow and marine life. There is also the ignorance that stems from the uninformed belief that New York cannot suffer from another Sandy, he said. 

HIT AGAIN? 

"It is really hard for people to grab onto the idea that we can get hit again," he said.

And finally there is the cost.

"But $20 billion is not a large amount of money," Abrahams said. "We've already spent that much on Hurricane Sandy. If you look worldwide and see what other major cities are doing, then maybe a different solution will appear more acceptable."

Haas said the gate option will be further investigated, but advocates the mayor's plan for its wide-ranging intentions. "The layered approach really looks at protecting the coastal edges, while also looking at building level protections and infrastructure protections," he said. "In lieu of one large, mega-project, a number of interventions and improvements that protect neighborhood-wide, area-wide, can really improve conditions.

"It's nearly impossible to climate-proof New York City. Somehow, Mother Nature is going to bring something that is beyond what was anticipated."